Laboratory
Safety
1
General Safety
Rules
If you have any medical condition which can affect
your ability to safely perform in the laboratory, report
it to the lab supervisor.
1. Listen to or read instructions carefully before
attempting to do anything.
2.Wear safety goggles to protect your
eyes
from
chemicals,
heated
materials, or things that might be
able to shatter.
3. Notify your instructor if any spills or accidents occur.
2
General Safety Rules
4. After handling chemicals, always
wash your hands with soap and water.
5. During lab work, keep your hands away from
your face.
6. Tie back long hair.
Do not apply makeup in the lab.
7.Roll up loose sleeves.
3
General Safety Rules
8. Know the location of the fire
extinguisher, eyewash station,
and first aid kit.
9. Keep your work area
uncluttered. Take to the lab
station only what is necessary.
4
General Safety Rules
10. It is suggested that you wear glasses rather
than contact lenses.
11. Never put anything into your mouth during a
lab experiment.
12. Clean up your lab area at the conclusion of the
laboratory period.
13. Never “horse around” or play practical jokes in
the laboratory.
In any emergency, the best way to take attention
5
of lab supervisor is to SCREAM!!
Chemical Safety
1. Wear
protective
goggles
whenever heating or pouring
hazardous chemicals.
2. Never mix chemicals together
unless you are told to do so.
6
Chemical Safety
3. Never taste any
chemicals (you should
never taste anything in
the lab).
4. If you need to smell
the odor of a chemical,
waft the fumes toward
your nose with one hand.
Do not put your nose
over the container and
inhale the fumes.
7
Chemical Safety
5. Follow the instructions of your instuctor
when disposing of all chemicals.
6. Wash your hands after handling
hazardous chemicals.
7. Never look down the opening of any
container even beakers, test tubes, flasks
8
Heating Safety
1. Use tongs and/or protective
gloves to handle hot objects.
2. Never reach across an open flame or
burner.
3. Always point the top ends of test
tubes that are being heated away from
people.
9
Heating Safety
4. When heating a test tube, move it around
slowly over the flame to distribute the heat evenly.
5. Only glassware that is
thoroughly dry should be
heated.
6. Heat glassware by placing
it on a wire gauze platform
on a ring stand. Do not hold
it in your hand.
10
1. DON’T PANIC!!
FIRE
2. If a small portion of your
clothes catch the fire, the
fire may be extinguished by
petting it out.
3. If a larger portion of your
clothes get the fire, there
are three options: i)drop to
the ground and roll, ii) use
the safety shower, iii) use
the fire blanket.
11
4.Never use a fire extinguisher
on a person.
5.If the fire occurs in a beaker
or in another container, cover it
with glass dish or another fire
retardant item.
6.Never move any object that is
burning.
7.Never use water to extinguish
any chemical fire.
12
8. If a fire is large enough to warrant the use
of a fire extinguisher, the proper use of the
extinguisher is as follows:
a)be sure the exit is behind of you,
b)pull out the restraining pin,
c)point the extinguisher hose at the base of
the fire,
d) holding the extinguisher upright squeeze
the handle to release the extinguishing media,
e) remember you may have 30 seconds for
pouring extinguishing media, so extinguishers
are only for use on relatively small fires.
13
First Aid
Injury:
To Do:
Burns
Immediately flush with cold
water until burning sensation is
lessened.
14
First Aid
Injury:
To Do:
Cuts, bruises
Do not touch an open wound without
safety gloves. Pressing directly on minor
cuts will stop bleeding in a few minutes.
Apply cold compress to bruises to reduce
swelling.
15
First Aid
Injury:
To Do:
The eyes
Flush eyes immediately with
plenty of water for several
minutes. If a foreign object is
lodged in the eye, do not allow
the eye to be rubbed.
16
17
18
REVIEW
19
After completing an experiment, all chemical
wastes should be
A.left at your lab station for the next class.
B.disposed
directions.
of
according
to
your
instructor’s
C. dumped in the sink.
D. taken home.
20
When you finish working with chemicals, biological
specimens, and other lab substances, always
A. treat your hands with skin lotion.
B. wash your hands thoroughly with soap and
water.
C. wipe your hands on a towel.
D. wipe your hands on your clothes.
21
All chemicals in the lab are to be considered
dangerous.
True
False
22
You have heated a piece of glass and now need to
pick it up. You should...
A.use a rag or paper towel.
B. pick up the end that looks cooler.
C. use tongs.
D. pour cold water on it.
23
When you do an experiment, long hair must be...
A. cut short.
B. held away from the lab materials with one
hand.
C. combed and neatly groomed.
D. tied back and kept entirely out of the way with
a hair band, hairpins, or other device.
24
In a laboratory, the following should not be worn:
A. loose clothing
B. Sandals
C. dangling jewelry
D. all of the above
25
Safety goggles must be worn and extreme care
taken when handling chemicals because:
A.they may stain clothing.
B. they react with the skin.
C. they may cause damage to eyes and skin.
D. they are highly combustable.
26
If a small portion of your clothes catch the
fire,
A. use a fire extinguisher
B. just tap it
C. use a fire blanket
27
If a larger portion of your clothes get the fire,
A. drop to the pool
B. drop to the ground and roll
C. use the safety shower
D. use the fire blanket
E. Use a fire extinguisher
28
In case of fire in a beaker in the lab
A. use a fire extinguisher
B. cover it with glass dish
D. take the beaker to the sink
E. Use water to extinguish fire
F. Use something like fire blanket to retard fire.
29
Correct and put in order the following instruction
rules about using an extinguisher
a) hold the extinguisher horizontally
b) be sure the exit is front of you
c) point the extinguisher hose at the top of the
fire
d) squeeze the handle to release the
extinguishing media
a) pull out the restraining pin,
30
Extinguishers are only for use on relatively
small fires. For emptying the extinguishing
media, you have only about
A. 30 min
B. 30 sec
C. 3 min
31
32
33
34
35
36
CHAPTER 2- UNITS AND DIMENSIONS
2.1 UNITS
All physical quantities have a numerical value and a unit. It is useful in most engineering
calculations- and essential in many- to write both the value and the unit of each quantity
appearing in an equation: 2 meters, 1/3 second, 4.29 kilograms.
In order to solve a problem effectively, all the types of units should be consistent with each
other, or should be in the same system. There are several different consistent systems of
units. In most of the world the SI system (Systeme Internationale d’Units) is standard. The
most commonly-used base units for the SI (kg-m-s) System are:
Table 2.1 Basic units for SI System
Dimension name
Symbol
SI unit
SI abbreviation
Length
L
meter
m
Time
t
second
s
Mass
m
kilogram
kg
Temperature
T
Kelvin
K
Electric Current
I
Ampere
A
Amount of substance
N
mole
mol
Each of these base units can be made smaller or larger in units of ten by adding the
appropriate metric prefixes in Table2.2.
Table 2.2 SI Prefixes
Factor
Name
Symbol
Factor
Name
Symbol
1012
Tera
T
10-1
deci
d
109
Giga
G
10-2
centi
c
106
Mega
M
10-3
mili
m
103
kilo
k
10-6
micro
µ
102
hecto
h
10-9
nano
n
101
deka
da
10-12
pico
p
1
2.1.1 Units of Common Physical Properties
Every system of units has a large number of derived units which are, as the name implies,
derived from the base units. The new units are based on the physical definitions of other
quantities which involve the combination of different variables. Below is a list of several
common derived system properties and the corresponding dimensions (denotes unit
equivalence). If you don't know what one of these properties is, you will learn it eventually.
Table 2.3 Commonly used SI derived units
Physical
Quantity
Force
Energy
Power
Pressure
Long SI Units
kg . m
s2
kg . m 2
s2
kg . m 2
s3
kg
m .s 2
SI Name
SI Abbreviation
newton
N
joule
J
watt
W
pascal
Pa
Equivalencies
mass .acceleration
N. m , Pa . m3
N.m
J
or
s
s
N
m2
2.1.2 Centimeter–Gram–Second System (cgs) System
The Centimeter–Gram–Second System, cgs system, uses the same base units as the SI
system but expresses masses and length in terms of g and cm instead of kg and m,
respectively. The CGS system has its own set of derived units, but commonly basic units are
expressed in terms of cm and g, and then the derived units from the SI system are used. In
order to use the SI units, the masses must be in kilograms, and the distances must be in
meters. This is a very important thing to remember, especially when dealing with force,
energy, and pressure equations.
2.1.3 American or English System
The English system is fundamentally different from the Metric system in that the
fundamental inertial quantity is a force, not a mass. In addition, units of different sizes do
not typically have prefixes and have more complex conversion factors than those of the
metric system. The base units and some derived units for different measurement systems
are given in Table 2.4 and 2.5.
Table 2.4 Base units for three measurement systems
2
Table 2.5 Some derived units for three measurement systems
To convert a quantity expressed in terms of one unit to its equivalent in terms of another
unit you can use the conversion factors. A large table of conversion factors is given in Perry’s
Chemical Engineers’ Handbook, also you can find them via the internet.
2.1.4 How to convert between units
It is frequently necessary to convert from one type of unit to another. In order to convert
between units, conversion factors are used. A conversion factor is a relationship expressed
by an equation where the entries on both sides of the equation are the same quantity but
expressed in different units. A few common conversion factors are
12in=1ft
1000g=1kg
60s=min
Each relationship can also be rearranged into the form of a ratio:
1=
12𝑖𝑛
1 𝑓𝑡
1=
1000𝑔
60𝑠
1 = 1 𝑚𝑖𝑛
1𝑘𝑔
Such a conversion is accomplished by multiplying the original number (with its units) by
appropriate conversion ratio to cancel out the original units.
For example a conversion from 14 inches to its equivalent number of feet would be
accomplished as follows:
(14𝑖𝑛) (
1𝑓𝑡
) = 1.1667𝑓𝑡
12𝑖𝑛
Please note that the “old” (original) unit is canceled out by conversion factor. In the last case
there is only the “new” unit. This conversion can be generalized by the following equation:
𝑤ℎ𝑎𝑡 𝑦𝑜𝑢 𝑤𝑎𝑛𝑡 = 𝑤ℎ𝑎𝑡 𝑦𝑜𝑢 ℎ𝑎𝑣𝑒 ∗
𝑤ℎ𝑎𝑡 𝑦𝑜𝑢 𝑤𝑎𝑛𝑡
𝑤ℎ𝑎𝑡 𝑦𝑜𝑢 ℎ𝑎𝑣𝑒
Many conversions require the use of more than one conversion factor, such as the following
conversion of 37759 inches to its equivalent in kilometers (km):
2.54𝑐𝑚
1𝑚
1𝑘𝑚
(37,759𝑖𝑛) (
)(
)(
) = 0.959 𝑘𝑚
1 𝑖𝑛
100𝑐𝑚 1000𝑚
This can be generalized by the following equations:
3
𝐺𝑖𝑣𝑒𝑛 𝑢𝑛𝑖𝑡 × 𝑓𝑎𝑐𝑡𝑜𝑟 1 × 𝑓𝑎𝑐𝑡𝑜𝑟2 × … … . .× 𝑓𝑎𝑐𝑡𝑜𝑟(𝑛 − 1) × 𝑓𝑎𝑐𝑡𝑜𝑟(𝑛) = 𝑁𝑒𝑒𝑑𝑒𝑑 𝑢𝑛𝑖𝑡
𝑈𝑛𝑖𝑡1 ×
𝑈𝑛𝑖𝑡 2 𝑈𝑛𝑖𝑡 3
𝑈𝑛𝑖𝑡 (𝑛 − 1)
𝑈𝑛𝑖𝑡 (𝑛)
×
×……×
×
= 𝑈𝑛𝑖𝑡 (𝑛)
𝑈𝑛𝑖𝑡1 𝑈𝑛𝑖𝑡 2
𝑈𝑛𝑖𝑡(𝑛 − 2) 𝑈𝑛𝑖𝑡 (𝑛 − 1)
A list of common used conversion factors can be found in Appendix A.
2.2- SOME IMPORTANT PHYSICAL QUANTITIES
2.2.1 Moles
A gram-mole (or just mole) of a chemical compound is defined as the amount of that
compound whose mass in grams is numerically equal to its molecular weight. Molecular
weight is associated with Avagadro’s number of molecules. Avogadro's number equals
6.022× 1023.
1 mol (or 1gmol) Carbon = 12 g Carbon= 6.022 × 1023 Carbon molecules
Molecular weight: The molecular weight of a molecule is the sum of the masses of all the
atoms that make up that molecule.

Atomic weight of oxygen (O) equals to 16 atomic mass unit units (amu)
Molecular weight (MW) of oxygen molecule (O2) equals to 2x16 = 32 amu
MWO2= 32 g O2/gmol = 32kg O2/ kgmol = 32 lbm O2/ lbmol
1 kgmol = 1000 gmol and 1 lbmol = 454 gmol

Sulfur trioxide gas is made up of sulfur and oxygen, whose atomic weights are 32.06
and 16.00 respectively.
MWSO3  32.06  3 x16  80.06 g / mol
Atomic weights of all elements can be found from Periodic Table of Elements.
Molar Calculations
Almost all of stoichiometry can be solved relatively easily using dimensional analysis, just
using units instead of numerical values:
grams x
moles atoms
x
 atoms
grams moles
Moles to Mass
“How many grams in 2.8mol of water?"
2.8 mol H 2 O x
18 g H 2 O
 50.4 g H 2 O
1mol H 2 O
4
Mass to Moles
“How many moles in 22.34 g of water?"
22.34g H 2 O x
1mol H 2 O
1.24 mol H 2 O
18 g H 2 O
Symbols
m:
the mass of a quantity of material
mA :
the mass of a particular species (A) in a mixture
n:
the number of moles of a material
n A:
the number of moles of a particular species (A) in a mixture
MWA: molecular weight of a particular species (A) in a mixture
mA = MWA. nA
Exercise:
Common table sugar is sucrose, C12H24O12. How many lbmol of sucrose are in a bag that has
a mass of 100lbm? How many kgmol?
2.2.2. Force
The force, F, to accelerate a mass , m, at an acceleration rate, a, is defined by Newton’s
second law as
F = m.a
The force that an object exerts on the earth’s surface is
Fweight = m.g
where, g is gravitational acceleration.
Table 2.6. Gravitational Acceleration at Sea Level and defined Units of Force
5
Exercises:
1. An object has a mass equal to 1 lbm. What is its weight in pounds-force (lbf)?
2. An object has a mass equal to 8.41 kg. What is its weight (a) in Newtons and (b) in
pounds-force (lbf)?
2.2.3. Pressure
Pressure, P, is the amount of force applied to the unit area of surface of an object in a
perpendicular direction.
P=F/A
Table 2.7 Commonly Used Units of Pressure
6
2.3 SOME IMPORTANT PROCESS VARIABLES
2.3.1. Density
The density, , of a material is the mass of a unit volume of that material.
=m/V
water,25ᵒC = 1.0 g/cm3 = 1000 kg/m3
Specific gravity is the ratio of density of a material to density of reference material (generally
water at 4ᵒC). Specific gravity is dimensionless.
Example:
Spesific gravity of a liquid A is 0.6, what is the density of A?
sg = 0.6
=?
Water = 1000 kg/m3
sg = 0.6
0.6 = A / Water  A = 600 kg/m3
Table 2.8 Examples of units of some process variables for three measurement system
2.3.2. Flow rate
Three common types of flow rates used are:
mass flow rate (ṁ or F): the mass of a material that passes a reference plane within a
unit time interval, Mass/time- g/min
molar flow rate (ṅ or F): the number of moles of a material that passes a reference
plane within a unit time interval, Mole/time- mol/min
volumetric flow rate (): the volume of a material that passes a reference plane
within a unit time interval, Volume/time- L/min
ṁ = .
7
2.3.3 Mixture composition
It is often important to describe the composition of the mixture- substances that contain
more than one chemical compound or species-.
Expressions of composition of Species A in a mixture are below.
=
Relationship between each terms can be defined as
ṁA = XA. ṁ = MWA.ṅA = MWA.yA.ṅ = MWA.CA.
ṅA = ṁA / MWA = XA. ṁ/ MWA = yA.ṅ = CA.
Conversion between Mole Fraction and Mass Fraction
Strategy for converting mole fractions (or percentages) to mass fractions (or percentages):
8
Strategy for converting mass fractions (or percentages) to mole fractions (or percentages):
Exercises:
1. One analysis of air produced the following approximate mole percentages:
N2: 78.03% O2: 20.99% Ar: 0.94%
What are the mass percentages of these components?
2. 5 kg KOH is dissolved in 10 kg of water. What is the concentration of KOH salt? What
are the mass and molar factions of each components? (H:1g/mol, K:39g/mol,
O:16g/mol)
3. In a production line flow rate of product mixture is 10 L/min. The desired product
concentration is 42% in this mixture. Spesific gravity of this mixture is 1.025. What is
the concentration of product A in kg/L? What is the flow rate of A in kmol/min?
MWA=192g/gmol
9
Some basic definitions:
Matter is defined as anything that has mass and volume.
Mass is a measure of an object's inertia.
Weight is a force created by the action of gravity on a substance.
Volume is a measure of the amount of space occupied by an object.
The fundamental building block of matter is the atom.
When an atom is defined by the number of protons contained in its nucleus, chemists refer
to it as an element. An element is composed of the same type of atom.
Compounds are composed of different type of atoms. More precisely, a compound is a
chemical substance that consists of two or more elements.
The smallest representative for a compound (which means it remains characteristics of the
compound) is called a molecule. Molecules are composed of atoms that have "bonded"
together.
Mixture is a material system made up of two or more different substances which are mixed
but are not combined chemically.
A homogeneous mixture is a type of mixture in which the composition is uniform and every
part of the solution has the same properties.
A heterogeneous mixture is a type of mixture in which the components can be seen, as
there are two or more phases present.
10
2.4 DIMENSIONS
A dimension is a measure of a physical quantity without numerical values, while a unit is a
way to assign a number to the dimension. For example, length is a dimension, but
centimeter is a unit.
There are seven primary dimensions (also called fundamental or basic dimensions): mass,
length, time, temperature, electric current, amount of light, and amount of matter. All
nonprimary dimensions can be formed by some combination of the seven primary
dimensions. For example,
Dimension of force: (𝐹𝑜𝑟𝑐𝑒) = (𝑚𝑎𝑠𝑠 ∗
𝑙𝑒𝑛𝑔𝑡ℎ
𝑡𝑖𝑚𝑒 2
) = 𝑚𝐿/𝑡 2
Dimensions of some commonly encountered physical quantities are given in Table 4.5.
Table 2.9 Dimensions of some physical quantities
2.4.1 Dimensional analysis
Any valid physical formula must be dimensionally consistent – each term must have the
same dimensions. It helps to understand the formulas that are used, to see how different
expressions are related to each other, and to commit the most important formulas to
memory.
11
In practice, dimensional analysis involves systematically keeping track of the physical
dimensions of every expression you write down.
The law of dimensional homogeneity: Every additive term in an equation must have the same
dimensions.
PROBLEM:
Verify each term in Bernoulli equation has the same dimensons. What are the dimensions of
the constant C?
12
Exercises
1. Perform the following conversions by determining the equivalent value of
the given number in the new units indicated:
800 mmHg
to
bar
4.9 atm
to
Pa
5N
to
lbf
2560 nm/s
to
m/min
1.4 days
to
mins
2m
to
in
1.5 g/s
to
lb/h
3.9cL/s
to
mL/h
to
gal
177lbmft/min
to
kg cm/s
5.8 J
to
kcal
to
btu/min
34 g/m
to
oz/in
25 °C
to
°R
25 °C
to
K
2
3
47ft
2
2
4.5x10 W
3
2
3
13
2
14
Appendix A.
15